Tetra ethyl ammonium bromide

Solubility of Tetra Ethyl AMMONIUM BROMIDE N(CsHj)4Br, and of Tetra Methyl Ammonium Bromide N(CH 4Br in Acetonitril. 

Ionic liquids [e.g. l-ethyl-3-methylimidazolium triflate (mp. —9 C) l-n-butyl-3-methyl-pyridinium chloride (mp. 98 °C) tetra- -butyl-ammonium bromide (mp. 130 °C)]... 

The highly hydrophilic alcohols, pentaerythritol and 2-ethyl-2-hydroxymethyl-propan-l,3-diol, can be converted into their corresponding ethers in good yields under phase-transfer catalytic conditions [12]. Etherification of pentaerythritol tends to yield the trialkoxy derivative and kinetics of the reaction have been shown to be controlled by the solubility of the ammonium salt of the tris-ether in the organic phase and the equilibrium between the tris-ether and its sodium salt [13]. Total etherification of the tetra-ol is attained in good yield when reactive haloalkanes are used, and tetra-rt-octylammonium, in preference to tetra-n-butylammonium, bromide [12, 13]. 

Next, process chemistry for the practical synthesis of 7b (MGS0028) is discussed (Schemes 3.5-3.7) [42-45]. First, the synthesis of key intermediate (+)-29 from racemic acetoxycyclopentene (34) is shown in Scheme 3.5 [43]. The key reaction in this approach was Trost s asymmetric ally lie alkylation reaction of ethyl 2-fluoroacetoacetate with 34, which afforded 35 in high yield and high enantioselectivity, especially when a bulky tetra-n-hexyl ammonium bromide was used as a phase-transfer reagent (89% yield, 94-96%... 

TMA = tetra-methyl ammonium, TPA = tetra-propyl ammonium, Et-Py- = N-ethyl pyridinium, DIQ-6 = 1,6 hexa-methylene bis (trimethyl ammonium bromide), DIQ-6 = 1,6 hexa-methylene bis (benzyldimethyl ammonium bromide) and DIQ-6 = 1,6 hexa-methylene bis (triethyl ammonium bromide). 

Cl-, Tetra-ethylammonium chloride, - bromide (Cfl,),N-F-, (n-C,H,UNn-Stearyltrimethyl-ammonium chloride Benzyltrimethyl-ammonium chloride, Benzyltri ethyl-ammonium -Girard reagent T Pyridinium ethiodide (CH )JS Br-Br ... 

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